1. Field of the Invention
The present invention relates to a substrate treatment apparatus and a substrate treatment method for treating a substrate with a chemical liquid. Examples of the substrate to be treated include semiconductor wafers, substrates for liquid crystal display devices, substrates for plasma display devices, substrates for FED (Field Emission Display) devices, substrates for optical disks, substrates for magnetic disks, substrates for magneto-optical disks, substrates for photo masks, ceramic substrates and substrates for solar cells.
2. Description of the Related Art
In production processes for semiconductor devices and liquid crystal display devices, a substrate treatment apparatus of a single substrate treatment type adapted to treat a single substrate at a time is used for treating a front surface of a substrate such as a semiconductor wafer or a liquid crystal display panel glass substrate with a chemical liquid. The substrate treatment apparatus of the single substrate treatment type includes a treatment chamber defined by a partition wall, a substrate holding and rotating mechanism which generally horizontally holds the substrate and rotates the substrate, a bottomed cylindrical treatment cup which accommodates the substrate holding and rotating mechanism, and a chemical liquid nozzle which supplies the chemical liquid to the substrate held by the substrate holding and rotating mechanism. The substrate holding and rotating mechanism, the treatment cup and the chemical liquid nozzle are provided in the treatment chamber.
The treatment cup includes a fixed cup, and a guard vertically movable with respect to the cup and capable of receiving a chemical liquid scattered from the substrate rotated by the substrate holding and rotating mechanism. A treatment liquid received by the guard flows on an inner wall of the guard into the cup.
In the substrate treatment apparatus, plural types of chemical liquids are often used. Where chemical liquids which are liable to cause a hazard when being accidentally brought into contact with each other or mixed together, e.g., a sulfuric acid-containing liquid such as a sulfuric acid/hydrogen peroxide mixture (SPM) and an organic solvent such as isopropyl alcohol (IPA), are used in combination (i.e., the chemical liquids to be used in combination are inappropriate for mixing thereof), the accidental mixing of the chemical liquids should be reliably prevented. In general, therefore, different treatment chambers are used for treatment with different types of chemical liquids as disclosed in JP2007-103732A. Where an inappropriate combination of chemical liquids are used for the treatment in a single treatment chamber, a so-called interlock process is employed for preventing the accidental mixing of the chemical liquids in the treatment chamber. In the interlock process, when one of the chemical liquids is supplied, the opening of a chemical liquid valve for the other chemical liquid is prohibited or, when a detected rotation speed of the substrate falls outside a predetermined rotation speed range, the opening of chemical liquid valves for the chemical liquids is prohibited (see, for example, JP4917469 and JP4917470).